This invention relates to passenger entrance ramp of a mass transit vehicle.
It is a requirement of many passenger transit vehicles that there be provided a ramp system at a doorway of the vehicle so that passengers in a wheelchair can conveniently move from the ground surface adjacent to the vehicle onto the floor of the vehicle for transportation in the vehicle.
One example of a ramp arrangement which is particularly convenient for low floor transit vehicles is shown in U.S. Pat. 5,391,041, issued Feb. 21, 1995 to the present assignee.
This arrangement of ramp is suitable for low floor vehicles because it is located at floor level without any necessity for storage under the floor, bearing in mind that the low floor configuration reduces the height of the floor to a position where there is little space under the floor for storage of ramp elements. However some telescoping ramps have been provided and stored under the floor of a low floor chassis. However these are limited in the variation in incline which can be provided and are subject to failure as a consequence of continuous exposure to the elements and damage from curbs and other obstacles.
The ramp construction of the above patent therefore provides a ramp panel which is pivoted at its inner edge to the structure and rotates through an angle slightly greater than 180xc2x0 from a retracted position lying flat on the floor inside the vehicle to a deployed position where it extends outwardly from the pivot axis and slightly downwardly into contact with the ground.
The length of the panel in a direction across the width of the vehicle is limited by the fact that the door is generally located at the driver compartment so that the length of the panel is slightly greater than one half the width of the vehicle. In a situation where the ramp extends from the floor height downwardly and outwardly onto a raised curb, the angle of the ramp is generally acceptable and is not excessive thus interfering with the movement of the wheelchair up a ramp and into the vehicle. However in a situation where there is no curb so that the ramp must accommodate the full height from the floor to the ground, the angle of the ramp may exceed a desirable angle. Some vehicles of this type have a kneeling action by which the front suspension of the vehicle is slightly lowered by a height of the order of two to three inches thus again reducing the angle of the ramp. However this is generally insufficient to provide a ramp of the required angle.
It is one object of the present invention, therefore, to provide an improved passenger entrance ramp for a mass transit vehicle which allows a reduced angle of the ramp without increasing the length of a primary pivoting element of the ramp and therefore its intrusion into the area of the driver""s compartment.
According to a first aspect of the invention there is provided a passenger entrance ramp assembly for a public transit vehicle, the vehicle having a door way through which passengers pass for entering or departing the vehicle with a bottom edge of the doorway at floor level of the vehicle, the ramp assembly comprising:
a support structure for mounting on the vehicle at the doorway;
a primary ramp panel arranged at the doorway for movement between retracted position within the vehicle and a deployed position in which the primary ramp panel is inclined from an inner edge downwardly and outwardly from the vehicle to an outer edge at the ground;
a secondary ramp panel having an outer edge at the bottom edge of the doorway and an inner edge generally parallel to the outer edge and spaced inwardly therefrom;
the primary ramp panel being mounted for pivotal movement relative to the secondary ramp panel about an outer horizontal axis at the outer edge of the secondary ramp panel through an angle of the order of 180 degrees between the deployed position and the retracted position such that in the retracted position the primary ramp panel is inverted on top of the secondary ramp panel;
the secondary ramp panel being mounted on the support structure for pivotal movement about an inner horizontal axis at the inner edge such that the outer edge and the outer horizontal axis move upwardly and downwardly between a raised horizontal position and a lowered position;
the primary and secondary ramp panels being arranged such that, in the retracted position, the outer edge is in the raised position so that both the primary and secondary ramp panels are substantially horizontal and, in the deployed position, the outer edge is moved to the lowered position so that the primary and secondary ramp panels form a common ramp surface inclined outwardly and downwardly from the inner edge of the secondary ramp panel to the outer edge of the primary ramp panel.
Preferably the primary ramp panel is arranged to float at the deployed position.
Preferably the primary and the secondary ramp panels are located at the same ramp angle when deployed.
Preferably there is provided a fixed horizontal platform panel arranged at the inner edge of the secondary ramp panel and extending therefrom to an innermost edge generally parallel to the inner edge of the secondary ramp panel.
Preferably the primary ramp panel in the retracted position overlies and covers the secondary ramp panel and at least part of the platform panel.
Preferably the platform panel, the secondary ramp panel and the primary ramp panel are equal in width.
Preferably the primary ramp panel is moved between the retracted position and the deployed position by a primary panel power actuator and the secondary panel is moved between the retracted position and the deployed position by a secondary panel power actuator and wherein there is provided a control for controlling actuation of the secondary panel power actuator separately from the primary panel power actuator such that the secondary ramp panel can be actuated to move to the deployed position only if required and only after the primary ramp panel has been deployed and rotated through an angle of the order of 170 degrees relative to the secondary ramp.
Preferably the primary ramp panel is moved between the retracted position and the deployed position by a primary panel power actuator comprising a hydraulic cylinder, a first pulley connected to the cylinder, a second pulley connected to a pivot shaft of the primary ramp panel and a flexible continuous member engaged around the first and second pulleys forming communicating drive therebetween.
Preferably the primary ramp panel is moved between the retracted position and the deployed position by a primary panel power actuator and the secondary panel is moved between the retracted position and the deployed position by a secondary panel power actuator and wherein the primary and secondary panel power actuators include hydraulic actuators and are operated by a common hydraulic circuit.
Preferably the primary ramp panel is movable manually from the deployed position to the retracted position.
Preferably there is provided an abutment member for contacting the primary ramp panel when moved to the retracted position for lifting the secondary ramp panel into the retracted position.
Preferably the primary ramp panel is mounted at the outer edge of the secondary ramp panel by a hinge for pivotal movement about the hinge.
Preferably the primary ramp panel is moved between the retracted position and the deployed position by a primary panel power actuator comprising a rotary hydraulic actuator, a pivot shaft and a right angle gear box communicating drive from the actuator to the pivot shaft.
Preferably the primary ramp panel is moved between the retracted position and the deployed position by a primary panel power actuator and wherein the primary panel power actuator is mounted on the support for pivotal movement about the inner pivot axis.
Preferably movement of the secondary ramp panel is actuated by a pair of crank members each arranged at a respective side of the second ramp panel and each having a support roller engaging a respective support track on the support member for support thereby, the crank members being connected to a transverse drive shaft connected across the second ramp panel and driven by a hydraulic actuator such that rotation of the shaft causes the cranks to raise and lower the second ramp panel.
Preferably and the rollers are free to lift from the respective support track to allow manual movement of the second ramp panel from the deployed position to the retracted position.
Preferably the shaft is rotated by a drive cylinder acting on a crank connected to the shaft with a dog leg drive link between the cylinder and the crank.